US1807513A - Ftjbnace conteol - Google Patents

Description

"T. w. DELANEY 1,807,513

FURNACE CONTROL Filed Oct. 12. 1929 May 26, 1931.

4 Sheets-Sheet l mvamori .71 Delangy ATTORNEY WITNESS T- W. DELANEY May 26, 1931.

FURNACE CONTROL Filed 061. 12, 1929 4 Sheets-Sheet 2 ATTORNEY Ma y 26, 1931. T. w. DELANEY 1,807,513

FURNACE CONTROL Filed .Oct. 12, 1929 4 Sheets-Sheet 5 ATTORN EY T ECE THOMAS W. DELANEY, OF ST. PAUL, MINNESOTA FURNACE CONTROL Application filed October 12, 1929. Serial No. 399,378.

This invention relates to furnace control The cylinder 16 is supported by its flange 17. for steam boilers. The cylinder has embedded therein a large The invention, has for its general object number of current conductors or wires 18. to provide an operating means whereby fur- The wires 18 extend longitudinally of the naces under steam boilers may be pesitively cylinder 16 and are arranged in spaced rela- 55' controlled by the rate of flow of steam from tion about the entire periphery of the cylthe boilers at all loads. inder with the lower end thereof terminat- It is also an object of the invention that ing to form a convolution of a spiral. The furnaces for a group of boilers may be o-plower end of each wire is projected to proerated to permit any one boiler to assume or vide an exposed terminal as indicated for s0 reject its portion of the total load. example at 19. The upper end portions of It is also within the scope of the objects of the Wires are embedded in the flange 17 and the invention that adjustments may be made extended as shown for facilitating the conwhereby one or more boilers in a group may nection of leads thereto.

be operated at a fixed load while other boilers Upon the flange 17 there rests a plate 21 in the group serve to absorb fluctuations in which supports a yoke 22. The'yoke 22 is the total load. formed with a collar 23 within which is ro-' Other objects relating to details of con tatable a nut 24 through which is threaded struction, combination and arrangement of the upper end of a stem 25. The nut 24 is 29 parts will hereinafter appear in thedetail defree to turn within the collar 23 but restrained scription to follow. 7 against longitudinal movement upon stem The invention is illustrated by way of ex- 25. A hand wheel 26 is keyed to the upper ample in the accompanying drawings, in end of nut 24. Stem 25 extends through an which: 7 axial bore provided in cylinder 16', and the v 25 Figure 1 is a schematic view of the control lower end of said stem supports a cylindrical apparatus of this invention for a boiler and tank 27 which surrounds the cylinder. 16 as its associated furnace, shown, and is made from current insulating Figure 2 is a view in elevation and partly material. The rod or stem 25 is further proin section of the pressure control switch or vided with a stop .28 whereby the rod 25 is i 30 apparatus and illustrating the manner in prevented from turning. a

which the same is connected'to a steam main, The cylinder 16 is further provided with" Figure 3 is a horizontal-sectional view two chambers or cavities as indicated at 29 taken substantially on the line 3-3 of Figand 30, and each chamber communicates with ure 2, two bores extending the entire length of the 35 Figured is a planview of the switch concylinder as indicated by the reference chartrol for the operating motor, 7 acters 31 and 32respectively.. Also, the cyl- Figures 5, 6 and 7 are cross sectional views inder has embedded therein ,a conductor 38 7 taken substantially on the lines 55, 66 which extends theentirelength of the cylinand 77 respectively of Figure i, and der and has its lower end exposed while its Figure 8 is a skeleton view of the pipe con upper end extends through the flange 17 as necting assembly. v indicated at 89 in Figure 1.

Referring to the drawings more particu- Two auxiliary tanks 40 and 41 are prolarly, 10 is a steam main, 11 a control pressure vided, the tank 40 communicating with chamtank, 12 a pressure control switch or appaber 29 through pipe 12 and tank ll com- 45 ratus, 13 a rotary switch and furnace control municating with chamber 30 through pipe 43. wheel, and 14: an electric motor for operating The steam main 10 is provided with an said wheel. I orifice plate of the usual construction as in As best shown in Figure 2, the unit 12 com- ,dicated at. 44. Assuming the steam flows in prises atank 15 within which there is posithe direction-of the arrow 45, then there octioned a cylinder v16 of insulating material. curs what may be termed a low steam pressure side and a high steam pressure side with respect to the orifice plate 14 in a manner well understood. The bottom of tank 40 is connected through pipe 46 with the high pressure side of steam main 10, while the low pressure side of said main is connected to the lower end of the tank 15 through pipe 47. The lower end of tank T1 is connected to an outlet of the pressure tank 11 through pipe 48. Pipe 46 is connected at the point shown with pipe 50 which in turn is connected with pipes a7 and T8. Pipe 50 is provided with valves 51 and 52. Also pipe 50 communicates with pipe 47 through pipe 53, and pipe 53 is provided with a valve 54. The pipe 50 further communicates in turn with pipe T6 by pipe 55, the pipe 55 including a valve 55. The connection between tank 11 and 41 is provided with a valve 48 and the connection between the high pressure side of steam main 10 and lower end of tank 15 is provided with a valve 47.

low referring to the furnace control wheel 13, 56 indicates a shaft driven by the motor 14, and 57 suitable reduction gearing driven by shaft 56 for rotating a shaft 58 which supports the wheel 13. The wheel 13 carries a multiplicity of contacts 59 to which the different conductors 18 are connected as illustrated in Figure 1. An adjustable clamping block 61 is attached to supporting frame of rotary switch by arm whereby disc carrying contact blocks may be manually adjusted and held stationary by clamp. A second arm 62 is carried by shaft 58, said arm preferably being of insulating material and carrying two conductor fingers G3 and 64.

The shaft 58 carries two earns 64 and 65. A guide link is provided for each cam, as indicated at 66 and 67, respectively. Each guide link is provided with a roller, as at 69, which is adapted to ride upon its associated cam. Also, each guide link is pivotally anchored as at 67 on supporting frame 60 there by causing each link toswing upon its pivot 67 with the rotation of the wheel 13 in either direction. Connecting rods 69 and 69 are pivoted on links 66 and 67 at roller axis and translate motion imparted to links by cams into rectilinear motion in direction desired. Opposite ends of rods 69 and 69 are connected to control ends of rods which are connected to control apparatus of furnace such as speed control of fuel feed, dampers, motor speed controller, etc.

The switch control for the motor 1 1 is shown in detail in Figures l to 7, inclusive, and comprises two switch units as indicated generally at 69 and 70. Each unit includes an electro-magnet, at 70 and 71, respectively, and a shaft 71, said shafts being in axial alignment and each carrying three contact-making arms, indicated at 72, 7 3 and 74 in each unit. The middle arm 7 3 in each case serves as an armature for its respective electro-magnet as illustrated to advantage in Figure 5. The contact arms for unit 69are substantially U-shaped, as shown in Figure 5, while the contact arms for unit (39 are straight, as shown in Figure 7. The switch control is housed in a suitable casing 7 5 which supports the electro-magnet 71 as well as shafts 71. The casing also supports a bracket plate 76 which in turn supports clectro-magnet 70 as shown in Figure 5. A compression spring 77 is provided for the outer contact arms 7274r for each s'vitch unit and arranged as shown in Figures 5 and 7, respectively. It should be noted that the two switch units are interlocked so that one switch in its closed position maintains the other switch in its open position and vice versa. Both switches may be open.

The contact arms 72, 7 3 and 74 carry suitable contacts 7 8 which are adapted for engaging stationary contacts 79 carried by the easing 75. The contacts 7 8 are connected to current supply leads 8() while contacts 79 are connected to the motor supply leads 81. Electromagnet 7 0 is connected in series with contact finger 63 and one of the supply leads 79 through leads 82 and 83, respectively, while electro-magnet 71 is similarly connected to contact finger 64 and one of the supply leads 79 through leads 84 and 85, respectivel 1t should be noted that the conductors 18 are connected to the contacts 59 of wheel 13, that the conductor 38 is connected to one of the supply leads 79 and that contacts 59 corre spond in number to the conductors 18. Also, it will be noted that the contacts carried by the arms of the switch unit 70 are comaected to the motor leads 81 in reverse order with respect to the switch arm coni'arts of the switch unit 69.

The shaft carries a brake drum S6 for which there is provided a split brake band 87, one end of which terminates in a lug 88 while its other end terminates in a finger 89. Between the lug 88 and finger 89 there is provided a pivoted sleeve 90 which is formed with a lug 91 and a plate extension 92. A stop-screw is threaded through lug 8S and adapted to engage lug 91. illso a stop-screw is tnreaded through platecxtcnsion and adapted to engage finger S9.

The shaft 71 of each switch unit carries an arm 93, the free end of which is adapted to engage upon the plate extension 92, as shown in Figure 4:.

Previous to the use of the apparatus heretofore described the tank 27 should be filled with mercury to the level of the first exposed lower end of conductors 18. Also the tanks 40 and 411 are partly filled with water and partly with oil of high electrical resistance. The oil should also fill the chambers 29 and 30 and their associated bores 31 and 39, respectively. The tank 11 is partly filled with water and then air pressure admitted equal to v boiler controlled, and

the operating steam pressure of a boiler. It is to be understood that a control apparatus as heretofore described is provided for each thus the outlets from pressure tank 11 will correspond to the munber of boilers or furnaces being controlled.

With the above conditions present, the proper valves are opened for bringing the pressure tank 11 into communication with the lower end of tank 41. Alsothe proper valves are opened for bringing the lower end of tank 0 n communication with the high pressure side of steam main 10 and the lower end of tank 15 in communication with the low pressure side of steam main 10. The high pressure side and low pressure side of steam main 10 exist on opposite sides of the orifice plate 44 as previously explained. Assuming the rate of steam flow in main 10 is such that the difierential pressure across orifice plate 44 causes mercury in receptacle or tank 27 to rise to a point to cover the lower terminals of a number of conductors 18, and that the contact fingers 63 and 64 are disposed upon contacts 59 connected to the conductors 18 having their lower ends covered by mercury, then an electrical circuit is established through each of the electro-magnets 7 O and 71 and the switch unit 70 is opened while switch unit 69 is closed. This results in rotating the motor 14 for imparting rotation to shaft 58 in a clockwise direction, and such rotation is continued until finger 64 has contact with one of the segment contacts that are connected to conductors 18 not contactin g with mercury in tank 27. Switch 69 then opens and motor remains stationary until change in level of mercury is effected. This rotation of the wheel 13 can be utilized in an obvious manner for increasing the fire beneath a boiler through one of the bellcrank levers 6667. When the fingers 63 64 leave contacts 59 and which not capable of establishing a circuit through magnets 70 and 71 then switch unit 7O will open and switch 69 close and thus reverse the direction of rotation of motor 14. The Wheel 13 will now be rotated counter-clockwise until the fingers 6364 reach contacts 59 that are connected with conductors 18 having their lower and exposed ends in contact with mercury within tank 15, at which time the direction of rotation of the motor 14 is stopped and. rotated in a clockwise direction in an obvious manner. This rotation of the shaft 58 and attached cams 64 and 65 can be utilized in an obvious manner for increasing the fire beneath a boiler through one of the guide links 66-67 and their connecting rods. When the level of mercury is lowered causing break in circuit through contact finger 63, switch 60 is closed by springs 7 7 causing motor to rotate shaft 56 in counterclockwise direction until finger 63 contacts segment 59 whose conductor 18 is immersed 1n mercury, thus open:

ing switch 69. Motor will now remain stationary until change in level of mercury occurs. It will thus be seen that each change in demand for steam will change level of mercury and cause motor and shaft 56 to rotate thus increasing or decreasing rate of combustion to meet new conditions.

The operation heretofore described would permit each boiler controlled from the pres.- sure tank 11 to assume its portion of load at all times. If it is desired that one boiler lead others in a group, that is, take more load than the others, the same may be accomplished by raising the mercury cup 27 through hand wheel 26. Also the same purpose may be accomplished by loosening clamp 61 and rotating wheel 13 clockwiseto increase combustion under the controlled boiler or counter-clockwise for decreasing combustion.

If it should bedesired to operate a boiler at a fixed load, valves 49 and 47 are closed and valves 54 and 55 opened thereby connecting chamber 29 with low pressure side of steam main and tank 15 with high pressure side of steam main. The mercury tank is now raised by hand wheel 26 until the proper regulation of the associated furnace is obtained for carrying a certain load. Under this condition any rise in steam pressure will cause rotation of shaft 56 to reduce such pressure counterclockwise as viewed in Fig. 1 and any lowering of steam pressure in steam main will bring about reverse rotation of shaft 56, thus increasing rate of combustion.

An increase in steam fiow above that for which furnace control is set will increase dif ference in pressure between inlet and outlet sides of orifice plate depressing mercury in tank 27 thus causing rotation of shaft counterclockwise to decrease rate of combustion.

While I have shown andldescribed thepreferred form of my'invention as well as the preferred combination and arrangement of parts constituting the same, I wish it to be be understood I am not to be so limited as indicated by the appended claims.

I claim 1. In combination a steam main changes ofsteam pressure therein, fluid pressure, connections between the steam main and constant fluid pressure, including pressure tanks filled with fluids, and means whereby the fluids will establishelectrical control circuits when the pressure in the subject to a constant steam main varies from the fluid pressure.

. '2. In combination a steam main subject, to changes of steam pressure therein, a constant fluid pressure, connections between the steam main and constant fluid pressure, press sure tanks interposed in said connections including container having mercury therein adapted to rise and drop in saidcontainer with change in pressure of steam mam wlth respect to flu d pressure, and means whereby electrical control circuits are established with change of level of mercury.

3. In combination a steam main subject to changes of steam pressure therein, a constant fluid pressure, connections between the steam main and constant fluid pressure, pressure tanks interposed in said connections including a container having mercury therein adapted to rise and drop in said. container with change in pressure of steam main w'th respect to fluid pressure, a plurality of conductors within the container arranged for establishing ditlerent electrical control circuits with hange of level of said mercury.

4. In combination a steam main subject to changes of steam pressure therein, a constant fluid pressure, connections between the steam main and constant fluid pressure, pressure tanks interposed in said connections including a container having mercury therein adapted to rise and drop in said container with change in pressure 0% steam main with respect to fluid pressure, a plurality oi conductor wires within the container having terminals exposed to the mercury when at different levels, and means whereby each cond ctor will establish an electrical circuit when contacting with the mercury.

5. In combination a steam main subject to changes of steam pressure therein, a constant fluid pressure, connections bet veen the steam main and constant fluid pressure, pressure tanks interposed in said connections including a container having mercury therein adapted to rise and drop in said container with change in pressure of steam main with respect to fluid pressure, means whereby electrical control circuits established with change of level of mercury, and means whereby said circuits are utilized for providing mechanical motions.

6. In combination a steam main having an orifice plate therein to provide high and low pressures on opposite sides thereof, a

constant pressure fluid source, fluid pressure tanks and connections between the constant pressure fluid source and the high and low pressure sides of the steam main, and neans associated therewith whereby electrical control circuits will be established when the pressures in said steam main vary from a predetermined relation to the constant fluid pressure.

7. In a "furnace control, a steam main having an orifice plate to provide high and low pressure on opposite sides thereof, a constant pressure fluid source, a pair of tubular pressure tanks one of which is connected to the constant fluid pressure tank and the other of which is connected to the low and high pressure sides of the steam main, a mercury column positioned between and responsive to the fluid pressure in said tanks and unitary control means responsive to the movement of said mercury for controlling the furnace.

8. In a furnace control apparatus, a steam main having an orilice plate providing high and low pressure on opposite sides thereof, an automatic switch control means having three tubular fluid pressure chambers connected to the high and low pressure portions of a steam main and a constant fluid pressure tank respcctivcly, a tubular column of mercury situated between said high pressure tubular chamber, said constant pressure tubular chamber and said low pressure tubular chamber and responsive to the pressure therein and unitary electrically controlled means responsive to the movement of said mercury for controlling the furnace.

9. In a furnace control apparatus, a mercury switch comprising three tubular chambers connected to the high and low pressure portions of a steam main and a constant pressure tank respectively, a column of mercury therein, adapted to respond to the pressure in the low pressure tubular chamber on one side thereof and the pressure in the high pressure tubular chamber and the constant pressure tubular chamber on the opposite side thereof, and unitary control means responsive to the movement of said mercury to control the furnace.

10. In combination, a steam main subject to changes of steam pressure therein, a constant fluid pressure source, connections between the steam main and constant fluid pressure, pressure tanks interposed in said connections including a container having mercury therein adapted to rise and drop in said container with change in pressure of said steam main with respect to fluid pressure, a plurality of conductors within the container, an electric motor, a control unit therefor, electrical circuits between said control unit and said conductors for rotating said motor in clockwise an d counterclockwise directions with change of level of said mercury.

THOldAS d DELANFY.

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